Declining rainfall, bugs, and birds

Instinct and the annual increase of daylight hours have long been thought to be the triggers for birds to begin their spring migration. Scientists at the Smithsonian Conservation Biology Institute, however, have found that that may not be the case. Researchers have focused on how warming trends in temperate breeding areas disrupt the sensitive ecology of migratory birds. This new research shows that changes in rainfall on the tropical wintering grounds could be equally disruptive. The team’s findings are published in scientific journal Proceedings of the Royal Society B, March 30.

Many of the bird species that breed in the temperate forests, marshes and backyards of North America spend the winter months in the tropics of the Caribbean, and Central and South America. Insects are the primary food for many birds during the winter, and rainfall largely determines the amount of insects available. Climactic warming, however, is causing declining and more variable rainfall cycles in many areas, affecting the availability of insects and delaying when birds leave for their northern breeding grounds. To examine this, the Smithsonian scientists focused on American redstarts (Setophaga ruticilla), a member of the warbler family, at a non-breeding site in Jamaica where they conduct long-term studies.

“American redstarts were a perfect species for this study since they defend exclusive territories throughout the non-breeding period until they depart for spring migration and most return back to the same territory the following year,” said Pete Marra, research ecologist at the Smithsonian Conservation Biology Institute’s Migratory Bird Center. “These behaviors made it relatively easy to keep track of individual birds over multiple years and document changing spring departures. Each individual was fitted with a unique combination of colored leg bands.”

Precipitation in Jamaica is highly seasonal, with consistent rainfall from September to November and a pronounced dry season from January to March. The scientists observed the redstarts in their non-breeding territories for five years during the dry season. They paid special attention to the annual variation in dry season rainfall. The correlation between the amount of insects in a bird’s territory and the timing of its departure suggested to the team that annual variation in food availability was an important determining factor in the timing of spring migration. Had the redstarts relied on internal cues alone to schedule their spring departure, they would have all left their winter territories at the same time each year.

“Our results support the idea that environmental conditions on tropical non-breeding areas can influence the departure time for spring migration,” said Colin Studds, a postdoctoral fellow at the Smithsonian Conservation Biology Institute’s Migratory Bird Center and lead author of the study. “We found that the same birds changed their spring departure from one year to the next in relation to the amount of rainfall and food in March.”

During the past 16 years, the dry season in Jamaica has become both increasingly severe and unpredictable, leading to an 11 percent drop in total rainfall during the three-month annual drought. Making the future even more dire, climate models predict not only increased warming on temperate breeding areas but also continued drying in the Caribbean.

A critical question for the scientists is whether this variation in the onset of spring migration carries consequences for the birds. Delaying departure could be beneficial if food resources are low and the individual has not yet stored enough energy to migrate. However, delaying departure could affect arrival time to its breeding territory and result in less time to successfully reproduce. “Because American redstarts return to the same site to breed each year, arriving later may make it harder for them remain to remain in synch with their breeding cycle,” Studds said.

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87 thoughts on “Declining rainfall, bugs, and birds”

Such presumption that correlation is causation, as always in these climate studies.

We have migrating swallows in my area of Greece. They leave in October and return in the spring. Tradition has it that they return in March, even folk poems say so. I have not seen my first swallow yet. Does that mean it has been wet in Egypt?

Storms can destroy swarms. One October, driving in Crete I had to stop because the road surface was alive with swallows drying in the sun. A storm had passed and threw them to the ground. The ones that were over the sea would have drowned.

I would think that the birds would gauge the weather, probably sensing highs and lows, and time their departure with that. Storms can really drown them in the sea . There would be a correlation with wetness, they will leave early if it is dry, to get the good weather, which is another possible hypothesis/ factor entering in this correlation.

“Making the future even more dire, climate models predict not only increased warming on temperate breeding areas but also continued drying in the Caribbean.”

It sure was lucky that the Beagle happened to land in the only island group on the face of the earth that has variable local conditions, or else Darwin might never have noticed that species are capable of adaptation to geography and climate. [/sarc]

“Delaying departure could be beneficial ” … Beneficial because it has been so damn cold here in western Canada these past few springs that LBJs and SSBs that arrive early are killed by snow and cold. Snow and cold was so bad last year we lost over 90 percent of our Canada goose crop (eggs and goslings) on the ponds across the road from my house. Hardy geese!

And the robins will get hammered again this weekend by big snow dump!

I liked the old, warmer version of GW much more the colder version of warming … and I know the birds do as well.

Climactic warming, however, is causing declining and more variable rainfall cycles in many areas, affecting the availability of insects and delaying when birds leave for their northern breeding grounds.

Too bad that the birds were not flying sooner because then they could have just blamed global warming directly instead of having to resort to this kind of stretch.

“Researchers have focused on how warming trends in temperate breeding areas disrupt the sensitive ecology of migratory birds.”

Not unless they are breeding in the heat sink cities. Of course “climate disruptions” can be blamed for changes in rainfall as well. Chalk another one up to CO2. It will never end until we take away the research funding.

Climactic warming, however, is causing declining and more variable rainfall cycles in many areas…

Right, can’t have a study like that without mentioning a climax…and the climax is now history?

It sure is a good thing that birds who live on insects know how to get around by flying from a declining source of food to a more plentiful one. I would think that a few hundred kilometers here or there is by far not as much a problem for such birds as is their twice-annual migration of a few thousand kilometers.

Did the study examine that? Perhaps it was just a bit too cozy for the researchers to go into more rainy areas to check that out. After all, they would have become all wet doing that.

This is just a guess, but an educated one, that somehow these birds survived the last ice age and the warming that followed it.

Maybe these ecologists issuing alarms are really Creationists at heart. Perhaps they think the World was created 6000 years ago just as it was in 1940 before we humans commited original sin through postwar industrializaiton. It would explain a lot.

“…During the past 16 years, the dry season in Jamaica has become…”
And the 16 years before that it was “normal”????
What about the 16 years before that, before that, before that….ad infinitum???

It sounds like we’re basing hysteria on a remarkably brief 16 year period, without mentioning an particular 16 year period in history with similar observations, and once again, the Models are like alarm sirens, but with no quantifiable reference, and no input of land use or other normal climate variation.

A critical question for scientists is whether this variation carries consequences???
Ya think?? The critical question should be how the birds have adapted in the past to shifts that were very likely much more severe, and part of the natural variability of climate.

Then go on to quantify exactly how much of the current change is anthropogenic….IF any.

Wow. Its almost like over thousands of years mother nature may have evolved a system where the birds will not migrate to their breeding grounds as quickly and therefore may have reduced winter #’s when drought may reduce the available food the next winter. Something must be done to overcome this immediately or we will lose traction of humans can control everything on the planet.

“Making the future even more dire, climate models predict not only increased warming on temperate breeding areas but also continued drying in the Caribbean.”
__________________________________________________
I was waiting for the global warming hook and they didn’t disappoint. Twenty years ago this would have just been an interesting biological observation. Today it can be passed off as a “significant finding” because of the threat of global warming. Then they had to repeat was “climate models predict”. Perhaps I’m cynical, but bird watching in Jamaica during the winter doesn’t seem like a bad gig. Obviously “more study is needed”.

You just know that AGW was worked into the grant proposal for this study.

So the birds have evolved the ability to sync their life cycle with a varying climatically regime. Why would they have done that? Either they anticipated mankind changing thins, or (now don’t laugh) maybe the climatic regime is naturally variable.

Gosh-another “team” finding of a dire problem due to (term now not used) global warming. It never ends. No humming birds in my area of S. Ala. yet. Is it wet or dry in S. America where they migrate from or do they know the weather up in the states is still too cold for them yet. A friend of mine sailing in the middle of the Gulf of Mexico had a flock of them rest on her sailboat masts on their way somewhere in the fall . They must have been taking a shortcut across the Gulf instead of going across Central America. I propose a new study(fully funded of course) to look into the path of humming birds and I think somewhere in the Keys would be a great place for “team” headquarters and only a 5 year study for the “team” to start sounds about right.

“Making the future even more dire, climate models predict not only increased warming on temperate breeding areas but also continued drying in the Caribbean.”

Really, a model predicts increased warming, and continued drying? Well it must be true… Until is isn’t, but then of course a new model will surface that predicted that very thing the whole time…

Of course, all the money spent on demonizing a trace gas, that if it was eliminated would kill us all is beside the point. I wonder how many studies there have been about the harm that progressive policies cause by diverting resources away from real world problems.

Billions of tax dollars down the drain to show migratory birds can predict climate better than climate models.

These migratory birds produce huge volumes of CO2 in relation to their size during their annual migrations. We need to tax this CO2 and thereby reduce the unnecessary migration, to slow the rate of climate change in Jamaica.

Like people, birds should not be allowed to cross borders without passports and proof of resources. They are fair-weather freeloaders. Traveling here without permission and taking the food from our local birds. It is high time someone built a fence and kept them back where they belong.

“Climactic warming, however, is causing declining and more variable rainfall cycles in many areas”
———————————————————————————————–
Article:
As Predicted, Global Warming Fuels More Tropical Rainfall
Scientists had predicted that global warming ought to increase rainfall in the tropics. Now NASA researchers say it has.

Scientists assembled a 27-year global record of rainfall from satellite observations and ground-based instruments and found that the rainiest years between 1979 and 2005 occurred primarily after 2001.

The wettest year in the record was 2005, followed by 2004, 2003, 2002 and 1998.

The patterns observed in the record showed that increases in rainfall were concentrated over tropical oceans, while there was a slight decrease over land.
=======================================================
Tropical Atlantic sees weaker trade winds and more rainfall

“Accompanying these changes in wind and ocean temperature is a very significant increase in rainfall, ”
=======================================================
TROPICAL WARMING BRINGING MORE FLOODS

A satellite study of tropical rains since 1980’s has shown a trend of more frequent flash floods and tropical downpours confirming computer model predictions of more cloudbursts due to human-made burning of fossil fuels.
Results of the study have been published in the journal Science and revealed extreme soakings were greater than most predictions.

The findings were based on a study of the tropical oceans, where satellites can more easily record rainfall. These trends were likely to be matched over land
=====================================================

A comparison of the old 30 year mean (1951-80) with the 1971-2000 mean by the
Meteorological Service has shown that the island’s rainfall patterns and values have not changed significantly for the current thirty-year (1971-2000) period. The main changes noted are that of wetter dry periods and drier wet periods. This has however not affected the overall rainfall pattern for the island.

“During the past 16 years, the dry season in Jamaica has become both increasingly severe and unpredictable, leading to an 11 percent drop in total rainfall during the three-month annual drought. Making the future even more dire, climate models predict not only increased warming on temperate breeding areas but also continued drying in the Caribbean.”

Notice that Jamaica says the dry periods are getting wetter, while the Smithsonian says the dry periods are getting dryer.

This is garbage.
We know little or nothing about what precipitates bird migration or how the birds navigate.
There’s a lot of speculation but very little evidence.
Whether or not the food supply for the birds is present upon their migratory arrival is simply happen-stance. Prime birds will survive. Less than prime birds will die.
It’s called ‘Nature’.

Maybe the birds can try out California or Hawaii where global warming has brought a great deal of rain. And at least in Hawaii, insects.
BTW. The relationship between rain and insects is not direct. You need substantial rain fall, say a quarter to an inch, with an intervening dry spell of 3 days to a week. More rain can indirectly kill larvae. Nor does the total rain matter much.

“The scientists observed the redstarts in their non-breeding territories for five years during the dry season.”

“………… arriving later may make it harder for them (remain) to remain in synch with their breeding cycle,” Studds said.

Five years of individual bird study at both ends and it only “MAY” make it harder. Well did it or did it not?How much delay was there on average over the five years. Did you note if one or two did have a bad time of it up north? Do all studies in climatology these days (or horrors! all sciences) start off with a presumption that has to be upheld. This study should have said, “So far the jury is still out on our hypothesis and we don’t yet know if anything other than instinct and the annual increase of daylight hours are the triggers for birds to begin their spring migration. We scientists at the Smithsonian Conservation Biology Institute have (not) found that that may not be the case.”

This is all in a day for a University TA but the Smithsonian needing this critique!

The Smithsonian scientists studied one particular subspecies of birds for 5 years, in a geographically very specific area of Jamaica, specifically during the 3 month long Jamaican dry season.

They found that the little birds departure flight schedule from Jamaica is more consistent when it rains more and their bug food is plentiful. It may be more variable when it is drier and bug food is in short supply in Jamaica.

From this, and a supporting cast of computer climate models (Ugh..), they conclude that AGW is ‘making the birdies future more dire’ because it may screw up their departure timing to travel from Jamaica up to their summer breeding grounds in the temperate forests and marshes of Wisconsin. To say this is ‘a stretch’ is a profound understatement!

A concentrated migration flight of the majority of the Redstarts may expose their numbers to catastrophic risk from single events like tropical storms. A more distributed over time migration may in fact be quite beneficial to population stability and over all breeding success!

It could equally be argued that, if AGW was a real phenomena, the summer breeding season in the temperate forests and marshes of Wisconsin (and all of the norther tier states and Canada) would be beneficially extended, allowing the little birdies to be more successful in their breeding and fledging of many more Redstarts!

Additionally, 5 years of data is an insufficient baseline to draw any meaningful conclusions about regional variations in Jamaican weather on the breeding success and long term population stability of Redstart migrations from Jamaica to Wisconsin.

Finally, all of the hyperbole embedded in this study can be adequately summarized as simply ‘Evolution In Action’. If the little Redstarts are adaptable (and I’m betting they are!), they will continue to adapt to regional variability in weather and continue to be successful breeders in the northern marshes and temperate forests. If they can not adapt, they will become extinct, as 99.9% of all animals that ever existed on the planet have over the last millions of years of earthly biosphere evolution.

Think of it as Evolution In Action, because that is exactly what it is. The weather, climate, atmosphere, oceans and land masses on this dynamic planet are constantly and naturally changing. There is no Perfect Stasis. There is no Ideal Condition. There is only continual change. All of the animal species and all other biota on this planet must continually adapt to these natural environmental changes…. or perish. That’s the way it works, naturally.

The endless pseudo-scientific drivel continues. Looks like the Smithsonian is yet another bastion of science that has fallen by the wayside. Don’t these people realise just how foolish these sort of conclusions make them look!

Stephen Brown says:
April 1, 2011 at 2:22 pm
This is garbage.
…………………….
It’s called ‘Nature’.

Perhaps survival of the fittest is more apt. Birds have been around much longer than humans and can adapt.

The more funding that goes into climate science the more nonsense we get churned out. These people go out to the field looking for evidence to confirm their beliefs. This has become a religion and it’s a travesty.

Shows of a map of the birds migratory extent, which includes a lot more than Jamaica, and includes this excerpt:
“Due to the extensive population of this species of bird, it has received an evaluation rating of Least Concern.”

I wonder why the Smithsonian scientists studied Jamaica? Would it have anything to do with its great beaches? Crystal clear waters? Rum? Warmth? Carefree semi-holiday? Why didn’t they look at birds in Chad? I picked the wrong career. ;O)

Shows of a map of the birds migratory extent, which includes a lot more than Jamaica, and includes this excerpt:
“Due to the extensive population of this species of bird, it has received an evaluation rating of Least Concern.”

“One measure of extreme precipitation shows an increase over this time period while the one analyzed measure of dry conditions, the maximum number of consecutive dry days, is decreasing. These changes generally agree with what is observed in many other parts of the world. ”http://adsabs.harvard.edu/abs/2002JGRD..107.4601P

Migrating birds have a lot more to worry about than a bit of warmth and dry weather. That’s the least of their problems. I’m wondering how the Japanese Snipe that visit my place in Australia in our summer and breed in the Honshu marshes got on with the tsunami. Then they have to cope with the huge Chinese and Korean coastal land reclamations, typhoons etc. We do need, though, to be aware of their problems and leave them a bit of space.

Exact numbers are unknown, but some experts estimate that each year domestic and feral cats kill hundreds of millions of birds, and more than a billion small mammals, such as rabbits, squirrels, and chipmunks.

“Maybe these ecologists issuing alarms are really Creationists at heart. Perhaps they think the World was created 6000 years ago just as it was in 1940 before we humans commited original sin through postwar industrializaiton. It would explain a lot.”

Now, that is worth some thought. I know they are steady-staters. They believe that Earth was pristine and unchanging until 1850 when Karl Marx first noticed a decline in the human condition. They are struggling to stop the decline before it becomes a runaway freight train and civilization returns to its pre-1850 state. Ironically, their method of stopping the decline is to so encumber human initiative that civilization will return to its pre-185o state.

“Instinct and the annual increase of daylight hours have long been thought to be the triggers for birds to begin their spring migration.”

The most famous migrant birds are swallows that migrate at the END OF SUMMER. The most famous example are swallows that migrate from the city og Goya, Corrientes province, I Argentina and fly for about 30 days to San Juan Capistrano abbey in Capistrano, California.

They travel from many cities in Argentina to Goya, and on February 19th, they depart towards California, arriving there on March 29th, sharp. There is a famous festival in Capistrano greeting the arrival of the swallows. They return to Goya and other cities in Argentina on October 23rd, every year –sharp.

The problem is that swallows have been departing from Goya one two and three days earlier than before. Warmists say that’s a signal that spring is arriving early –but swallows have no internet connection or Watch TV to check how the climate is in California. They simply feel that temperatures are falling more than usual (as has been happing in Argentina) and say “let’s blast off, before it gets too cold here!”

“The amazing journey takes the swallows over 12,000 miles round-trip. They abandon their winter haven in Goya, Corrientes, Argentina and travel to southern California, arriving on St Joseph’s Day (March 19th) and then begin the return trip to Argentina on the Day of San Juan (October 23rd).”

“Just why the swallows’ migration has changed is up for speculation.

Locals and visitors alike have celebrated the annual migration of the swallows for as long as some of us can remember, and it is disappointing to those who show up for the Swallows Day Parade only to find the avian ambassadors missing.

So the Smithsonian Conservation Biology Institute should come down to Argentina and check for a variation to their hypothesis.

Algebra says:
Climactic warming?
——————-
Yes, its the latest name for Global Warming. I noticed this new branding in todays “The Vancouver Sun” where the term used was Climate Warming, in an article about “How all the fish are gonna die from the hot river water” or something like that.

Since we have up to 6 pairs of redstarts breeding on our land every year, and I’m a birder, this is interesting… but stupid.

What they are basically saying is that migrating birds respond to the real world. Any birder knows this. But they don’t seem to realize that this screws up their AGW apocalypse story about all the birds migrating like clockwork and dying off because spring hadn’t arrived, etc.

Also, this story implies that there is some tightly limited window when these (or any) birds can successfully breed. But their arrivals and departures vary annually and some bird nest later than others. Moreover, look at the huge breeding distribution of the redstart and you can see how flexible they are overall.

So, more desperate and stupid efforts to link the climate to something.

His family lineage having evolved over 1000s and 1000s of years and the ability to fly for long distances, probably prepares him just fine for drought and other inconveniences.

Hey Smithsonian! Don’t insult his intelligence.

He can adapt to a changing climate….whatever nature brings him.

Unfortunately, it seems, homo sapiens can’t.

Too stupid.

They are too busy barking up the wrong tree chasing after the CO2 molecule while rest of the biosphere passes them them by, evolving as they go [including generations of adaptable redstarts].

How Science in all its august splendor, which has brought us so much knowledge, understanding, technology, and advancement, has DEVOLVED into this CIRCULAR reasoning game “peer reviewed research” using catch-phrases such as “climate models predict and “a warming world” etc. etc, ad nauseum…is BEYOND ME!

Shameful.

I’ll bet if that little handsome bird in the picture could laugh…he would be laughing at US!

Getting near the end of a lifetime’s work as a Civil Engineer, I see that here we have a bunch of guys and gals being paid by the kind US taxpayer to spend their days spotting birds in Jamaica.

No doubt they have a nice inflation proof pension to look forward to. No doubt they also get to fly around to a few nice all-expenses-paid “conferences” in exotic locations to break the monotony.

Only snag is that they have to produce a few doom-laden prognoses with citations of climate modelling papers. But no doubt they have computer software that produces the bare bones of this, just at the click of a mouse.

Meanwhile, the little tweetie-pies keep on happily doing their own thing, seemingly without a care in the world (apart from the feral cats).

I have to scratch my head and wonder, why weren’t there careers like that available when I was a bright young graduate?

Since all of these “scientists” seem bound and determined to deprive green plants, to the greatest extent possible, of the always scarce (less than 40 molecules per 100,000 molecules) carbon dioxide that is absolutely required for the growth of plants that produce the food birds eat, I tune out.

The future can not be predicted by extrapolating the recent past into the future. ASSUME makes an ASS out of U and ME every time, if we go along with unfounded speculations, oftentimes nowadays called “theory”.

We had something along these lines last year in the UK ,the scare story was small birds were rapidly declining in numbers.
However when the RSPB did a survey this year they discovered the populations of small birds were actually thriving.
In fact this article I hate to say is from the Guardian,yuk.
Just scaremongering ,again.

It sure was lucky that the Beagle happened to land in the only island group on the face of the earth that has variable local conditions, or else Darwin might never have noticed that species are capable of adaptation to geography and climate. [/sarc]

The sad thing is, too many people think that “conservation = environmental stasis”. Any change at all from what they decide are ideal conditions is a Bad Thing, even if it’s 100% natural.

if they(enviros) cared about birds they’d be worried about (human)population increase and the inevitable resultant habitat destruction….here in the U.S. the population increase is driven entirely by illegal immigration, so when the enviros dare to speak about curbing/stopping illegal immigration i’ll be happy to take them seriously again, until then “yawn”…

and these kind of studies with “global warming is going to cause this and that and the other” just go in one ear and the other now because i just can’t help but picture these “scientists” getting a pat on the head and a few quarters from uncle Algore for putting out this claptrap…

I though the windfarms will be killing them. Strange for Al Gore, his Silent Spring might come after all, via windfarm, even night will be dead for ultrasound as all the bats will be dead. The whales are also getting beached from the ocean wind farms.

The assumption that the climate is always hotter and dryer does not reflect the reality of the last few years. I would encourage the author to study changes in patterns related to cold and wet also.

Reports on unexpected changes to migration patterns for bees, animals and birds have been reported for the last decade+. Climate could impact migration patterns but changes in the earth’s shifting magnetic fields would certainly drive them.

Are there sudden changes to fields due to magnetic burps from the earth that cause birds to fall in mass from the sky? Is the current magnetic shifting pole interfering with an animal’s ability to navigate to the correct seasonal target location or causing the animal to choose a new, more suitable location?

Bird specialists should deign to ask amateurs who are a well known resource to ornithology about the adaptability of birds. I grew up in Winnipeg, Manitoba and after an absence of 25 yrs returned one summer to see cardinals and blue jays that never were found in these parts when I was a boy. For some reason the range had shifted westward. Also, here in Ottawa, Ontario, a small flock of ducks winter over in a melted stretch of th Rideau R. where some warm outflow (from a hospital nearby?) Keeps it from freezing. These birds are more cunning, adaptable and individualistic than than your average biologist.

1. PhD’s are only available if the student can do ‘original research’
2. Student’s adviser needs more research funding
3. Original research is getting difficult to find
4. Politically based funding for ‘climate’ studies is the only relatively easy research funding
5. Student adviser and doctoral student try to think up a ‘catastrophic climate change’ angle in their specialist area of real-time underwater basket weaving
6. “Drought caused by catastrophic climate change !!” (doesn’t matter if there is or is not drought there’ll be a model somewhere that says there is)

This is the generation cycle of modern PhD research and as the AGW hypothesis is unfalsifiable and no PhD adjudicators dare appear to disagree with it – thesis defense is so much simpler.

1. Spring conditions do not effect insect emergence. That would be the first null hypothesis. They needed a model for that? Ah. Less expensive. And no one cares about the field studies done decades ago that essentially mapped out this insect behavior tied to spring conditions.

2. Insect emergence does not effect bird population. That would be the second null hypothesis. They needed a model for that? Ah. Less expensive. And no one cares about the field studies done years ago that essentially figured this relationship out.

Field research is so yesterday. And models are cheaper. Problem is, no one is running models under cold conditions. Does this mean that if we get colder, the birds will do just fine because the insects will emerge right on schedule? Everybody in Wallowa County understands: warm = insects, cold = insects gone.

Over here in the Old World, many European breeding warblers (and other birds)spend winter in the semi-arid Sahel zone of Africa located between the Sahara Desert and the rain forests to the south. The climate is dry All winter. The birds arrive in autumn after the end of the summer rains which, in good years, provide ample insects and other food for the next 6 months. Their over-winter survival and spring departure dates are thought to be linked closely with the highly variable rainfall amounts in the preceding summer. In severe and prolonged droughts in the 1970-80s some species populations were much reduced but others were little or not affected. Numbers of all gradually recovered with a return to more ‘normal’ rainfall patterns. In the sahel, there have been cycles of drought for the last 200 years.

Declines in many of our summer migrants that come north from West Africa to breed here are now considered to be caused by breeding habitats deterioration across Europe (a consequence of EU agricultural policies) combined with a rapid expansion in habitats degradation and destruction in West Africa. In that region, rapidly increasing human pressures and expansion are destroying large areas of Sahel vegetation cover ( by livestock overgrazing and for fuel) . This leads to a spread of ‘desertification’ at the northern edge of the Sahel, and further south (it is increasingly suspected) to reduced precipitation in summer. Rain forests are being felled on a large scale further south again.

In both continents the increasing environmental degradation would seem likely to have greater adverse ffects on our migrants than any caused by putative climate warming/changes. It would be interesting to have, for comparison, corresponding data for Jamaica and throughout the breeding and winter ranges of North American migrants.

The robust global hydrological response to global warming means that some areas will get heavier downpours and some areas of the planet will actually get drier. This is a complex response with many interacting pieces but the net effect globally however, of increased CO2, is for greater rock weathering as a result of changes in the global hydrological cycle, as fundamentally, that is the natural negative feedback response which removes CO2 from the troposphere and keeps CO2 within A RANGE. Obviously, with such a robust hydrological response, some species disruption can be expected. An excellent starting paper on this can be downloaded at:

Eduardo Ferreyra says:
April 1, 2011 at 7:21 pm
The problem is that swallows have been departing from Goya one two and three days earlier than before.

The problem is also that most of the SJC swallows no longer return to the mission. Some say development has reduced the available insects near the mission, and this change in available prey has caused the birds to nest elsewhere in the area.

I couldn’t find a reference now, but I think I read that the nests at the mission were relocated. I know that Barn and Cliff swallow nests were destroyed at Mission San Luis Obispo de Tolosa, further north, when a few people complained about bird poop on their fabulous garments. Where once there were clouds of swallows over the missions, now there are none.

As others have said, the dangers to songbirds are primarily man-made obstructions, habitat destruction, and especially, the free-roaming house cat, but probably not the weather.

R. Gates says:
April 2, 2011 at 10:40 am
The robust global hydrological response to global warming means that some areas will get heavier downpours and some areas of the planet will actually get drier. This is a complex response with many interacting pieces but the net effect globally however, of increased CO2, is for greater rock weathering as a result of changes in the global hydrological cycle, as fundamentally, that is the natural negative feedback response which removes CO2 from the troposphere and keeps CO2 within A RANGE. Obviously, with such a robust hydrological response, some species disruption can be expected. An excellent starting paper on this can be downloaded at:

The thing that is “robust”(and the only real hot air to speak of) is the circular reasoning that continues to propagate in this “research”, as well as the robustness of your own use of the word “robust.”

As Pamela Gray mentioned earlier with the only assumptions that only warming will occur….what happens if they are wrong and it turns colder?

And if it does, that adversely affect the little redstart fella more?

Until they stop with the assumptions based on “climate models predict” and “a warming world”…they, as researchers funded by the taxpayer….are just as guilty of circular reasoning as non-researchers like yourself, any old day.

R. Gates says:
April 2, 2011 at 10:40 am
The robust global hydrological response to global warming means that some areas will get heavier downpours and some areas of the planet will actually get drier.

============================

He [the lil’ redstart in the picture….lets call him Ricky the Redstart] can adapt to a changing climate….whatever nature brings him.

Unfortunately, it seems, homo sapiens can’t.

Too stupid.

They are too busy barking up the wrong tree chasing after the CO2 molecule while rest of the biosphere passes them them by, evolving as they go [including generations of adaptable redstarts].

Interesting study. It is only when the author attempts the splice with “Global Warming” that the rot sets in.

I think such splices should be written in a different color of ink, and that there should be a computer program that automatically deletes that section of papers and articals. What we would be left with is the interesting dicoveries.

Some birds seem to arrive in a manner you can just about set your watch to. The swallows returning to Capistrano (spelling?) and the buzzards returning to Hinkley(spelling?)

However warblers are more variable. There is a neat thing that sometimes happens that birders call a “warbler wave.”

A “warbler wave” occurs when the warblers are held up by persistant northwest winds and a late season cold snap. If some sort of blocking pattern keeps the cold weather in place, a sort of traffic jam of warblers develops down in the buggy marshes of Virginia and North Carolina, as the bird await a change in the wind.

Then, when the cold spell breaks and the wind shifts to the southwest, and at long last balmy breezes flow over New England, unbelivable amounts of warblers ride that wind. It is not only the species that live in New England, but also species that live further north. And the birders have a blast, stumbling through thickets with binoculars pressed to their noses, looking left and looking right and seeing a multitude of species whichever way they look. And I myself have to admit it pretty cool to be working outside, and to have such a singing flitting by all day.

R. Gates says:
April 2, 2011 at 10:40 am
The robust global hydrological response to global warming means that some areas will get heavier downpours and some areas of the planet will actually get drier. This is a complex response with many interacting pieces but the net effect globally however, of increased CO2, is for greater rock weathering as a result of changes in the global hydrological cycle, as fundamentally, that is the natural negative feedback response which removes CO2 from the troposphere and keeps CO2 within A RANGE. Obviously, with such a robust hydrological response, some species disruption can be expected. An excellent starting paper on this can be downloaded at: